Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Des Moines Iowa
640 PM CDT Monday Sep 1 2014

..updated aviation discussion...

Short term /tonight/...
issued at 333 PM CDT Monday Sep 1 2014

Weak instability remains over Iowa this
afternoon and has resulted in a few showers and isolated weak
thunderstorms. This activity will gradually diminish with the loss
of daytime heating. Another vigorous short wave is currently
moving moving into western Nebraska. The kinematic forcing
associated with this system will arrive across Iowa late this
evening. Sounding profiles are much drier than over the past week
and thus the system will be a bit moisture starved...but still
there will be enough forcing for scattered showers and a few
thunderstorms across northern Iowa overnight. Light winds tonight
and the recent rainfall and wet ground may lead to some fog
development under The Breaks in clouds.

Long term /Tuesday through Monday/...
issued at 333 PM CDT Monday Sep 1 2014

A few more chances of rain through the week...then looking dry for
the weekend. Tail end of a week shortwave to be moving through
the north early Tuesday so may have a few lingering
showers/isolated thunderstorms across the far North/East.
Otherwise dry conditions expected for the remainder of Tuesday
into Tuesday evening. Upper level wave to dig into the
intermountain west...with an associated surface low developing in Lee
of The Rockies. The associated warm front will lift northward
across the County Warning Area late Tuesday night into Wednesday. Strong moisture
advection expected as have continued the precipitation chances
for late Tuesday night into Wednesday Wednesday night. Thermal
ridging then builds into the County Warning Area for Thursday...with 850 mb temperatures
pushing into the middle 20s celsius. Surface low to lift from eastern
South Dakota into southern Ontario through the day...dragging a
trailing cold front through the County Warning Area late Thursday into early
Friday. This will bring the next chance of widespread rainfall as
the frontal boundary drops through the County Warning Area. A large area of high
pressure then builds into the region for late Friday into the
weekend. This will bring much drier and cooler air to the
state...with high temperatures only in the 70s for the weekend.
Return flow sets up in the lower levels...with southwest flow
aloft toward the latter portion of the weekend into early next
week. This will bring a return for precipitation chances to much
of the area.


issued at 635 PM CDT Monday Sep 1 2014

VFR conditions will prevail during the entire forecast period.
Although there still remains a chance for some MVFR fog to develop
overnight tonight but with lingering cloud cover and winds staying
just strong enough...left out mention at this time. Will
reevaluate with 06z tafs.


Dmx watches/warnings/advisories...none.



Short term...donavon
long term...beerends

National Weather Service Glossary of Abbreviations